Process for the dimensional control of cellulosic materials



United States Patent 0 PROCESS FOR THE DIMENSIONAL CONTROL OF CELLULOSIC MATERIALS Bernard H. Kress, Lafayette Hill, Pa., assignor to Quaker Chemical Products Corporation, Conshohocken, Pa., a corporation of Pennsylvania No Drawing. Application December 19, 1956 Serial No. 629,224

6 Claims. (Cl. 8-116) This invention relates to a process for dimensional control of cellulosic materials by application of certain acetal condensation products to cellulosic fabrics, yarns or fibers, such as rayon and cotton, in order to. obtain dimensional control or stabilization of the fabric, yarn or fiber against progressive, dimensional shrinkage under repeated washings. It also relates to the treatment of paper and paper fibers with said acetals in order to develop dimensional control and to increase wet strength.

A considerable body of both theoretical and practical literature has been built up around the use of formaldehyde and polymers thereof in order to limit shrinkage and dimensional control of cellulosic fibers. Dimensional control has been usually obtained at the expense of fabric strength, i.e. considerable tendering accompanies such treatment.

The use of formalin solution has never been widely accepted because of the difliculty of adequate control of the procedure and the volatility of the formaldehyde. This factor alone militates against wide use because irritating and harmful vapors are present and released during the entire process, and considerable loss of formaldehyde content occurs.

It is well known in the art to treat cellulosic materials, for purposes of dimensional control, to stabilize same against progressive dimensional shrinkage under repeated washings, with water-soluble urea or melamine formaldehyde condensates in the presence of acidic or potentially acidic catalysts. It is also well known to apply free aldehydes, such as formaldehyde and glyoxal, to cellulosic materials in the presence of acidic catalysts in order to achieve dimensional control.

It is a well-known and well-recognized fact that the urea and melamine condensates possess inherent disadvantages which limit their field of usefulness. For example, objectionable odors may develop in the fabric after finishing. Some of these condensates bring about considerable tendering and embrittlement of the fibers, thereby lowering the fabric tensile strength. These condensates also possess the unfortunate property of retaining chlorine. Thus, fabric treated with these condensates and subsequently bleached during laundering with chlorine-containing bleaches, will retain this chlorine and release it as hydrochloric acid when the fabric is ironed. This hydrochloric acid seriously tenders the fabric to the extent that these urea and melamine formaldehyde condensates cannot be applied to white or pastel shades which may be bleached during laundering. Furthermore, it has been observed that the degree of durability to laundering obtained through the use of these condensates is rather limited.

It is also well known in the art to use combinations foregoing difliculties by providing a process in whichno objectionable odors are developed on the goods. The

Patented Sept. 8, 1959 tendency toward tendering of the fabric is reduced. The agents used can be readily applied and controlled. The resulting treated textile materials are also non-chlorine retentive.

In my copending application, Serial No. 403,057, filed January 8, 1954, now patent No. 2,785,949, I have described the use of polyacetals derived from monoalkylene, dialkylene glycols, or polyalkylene glycols and an aldehyde, specifically formaldehyde, for the dimensional stabilization of cellulosic fabrics and in my copending 1 application, Serial No. 508,318, filed May 13, 1955, now

In its preferred form, the present process resides in treating cellulosic materials with a polymeric acetal condensation product of ethylene oxide and formaldehyde and curing under acidic conditions. Polymeric acetals derived by condensation of other olefin-oxides such as propylene oxide and butylene oxide and the like with formaldehyde or other aliphatic aldehydes containing from 1 to 8 carbon atoms in their monomeric form may also be employed. Likewise polyacetals derived from these oxides and aldehyde-generating materials such as methylal, paraformaldehyde, trioxane, paraldehyde and the like may also be used.

Preparation of some of the compositions useful in this invention is described in US. Patent 2,395,265, February 19, 1946, of William F. Gresham.

In order to explain this invention the following illustrative examples are shown.

Example 1 I short time and then warmed on a steam plate for several hours. Gaseous ammonia was then added in sufiicient amount to neutralize residual-catalyst. After filtration and heating to 100 C. at about 5 mm. vacuum to remove dioxolane and other volatile material, the product,

' amounting to 180 parts by weight, was a tan-colored syrupy liquid which dissolved in water and which was applied to rayon challis by the method of Example 2, giving shrinkage results shown in that example.

Products, such as the one described in Example 1,- have been found to be of value in the dimensional con trol of rayon and cotton fabrics without serious loss of tensile strength. The general application of these po1ymeric acetals involves padding cellulosic fabric through.

aqueous solutions or dispersions of the polymeric acetals containing from 0.5 to 25% by weight of the acetal. The

padding bath must contain, in addition to the acetal, some acidic-type catalyst, such as aluminum chloride, stannic chloride, aluminum sulfate, oxalic acid, zinc chloride, sodium acid sulfate, sodium or potassium alum, dimethyl oxalate, ammonium chloride, etc., in amount of about 5% to about 200% by weight of the acetal content. The

treated fabric may then be dried at an appropriate temperat'ure and subsequently cured at a temperature of at least 250 F. for about /2 to 10 minutes. .The time,

of cure varies inversely with the, temperature. The cured fabric may then be washed lightly with a detergent and a mild alkali, rinsed thoroughly and dried in a relaxed state. Fabrics so treated with these acetals will not undergo progressive shrinkage even when laundered in boiling soap solution as in American Association of Tex tile Chemists and Colorists (A.A.T.C.C.) 1952 Standard Test Method 14-52 for cotton and linen fabrics.

Example 2 1 Wash, Warp, Fabric Warp Tensile,

Shrinkage, Lbs.

Percent Treated as in Ex. 2... 0.0 50. 3 Untreated 7. 7 50. 5

Wash test-A.A.T.C.O. 1952 Standard Test Method 14-52.

Tensile strength-Federal Spec. COO-T-191B Method 5102-2" width.

Thus, the original dimensions are held even when subjected to a severe washing procedure. It should be noted that virtually no loss in tensile strength occurred from the treatment.

Other equivalent procedures may be used in preparing these condensation products. Thus, for example, dioxolane, obtained as an intermediate in reaction between one mole of ethylene oxide and one mole of formaldehyde may be used in place of the oxide itself. The ring in 1,3 dioxolane is opened by further reacting with formaldehyde as shown in Example 3 to obtain higher condensation products of ethylene oxide and formaldehyde.

Example 3 Parts 1,3 dioxolane ...4 74 Paraformaldehyde 16 Sulfuric acid 98% 1 The mixture was refluxed for 4 hours and a viscous, colorless water-soluble liquid was obtained.

Example 4 The product prepared in Example 3 was evaluated in the manner described in Example 2 on rayon challis. The catalyst consisted of a mixture of zinc chloride and diglycolic acid in a ratio of 1:4. The results are shown in the table.

1 Wash Percent Product in Bath, Catalyst, Warp Tensile,

Example 3 Percent Shrinkage, Lbs.

Percent 15 2 2.0 38.7 1 8 0. 0 33. 8 Untreated. 11. 49. 5

from 5% to 200% of the condensation product. Cures may be effected at temperatures of 250 F. and up to whatever is commercially practicable in order to obtain interaction between cellulose and the reactant to stabilize the cellulose.

The polyacetals of the present invention may be used in a similar manner to treat paper or paper fibers in any stage of their manufacture in order to develop wet strength and dimensional control with respect to atmospheres of fluctuating humidity. In such treatments, I prefer to employ the acetal in amounts ranging from about 0.02% to about 15% by weight of the dry cellulose or from about 0.175% to about 5% by weight of the treating bath and the catalyst in amounts varying from about 10% to about 285% based on the weight of the acetal. In paper treating, both process and results are similar to those described, using other polyacetals, in my copending application Serial No. 508,318, filed May 13, 1955.

Besides being used alone the products described in this application may be used along with the products described in my 'copending application, Serial No. 403,057, filed January 8, 1954, and with those described in my copending application Serial No. 508,318, filed May 13, 1955.

The products described herein may be modified further by organic acids or anhydrides such, for example, as acetic acid, acetic anhydride, butyric acid, 2-ethyl hexoic acid, cyclohexyl acetic acid, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, mellisic, stearic acid, benzoic acid, oxalic acid, succinic anhydride, adipic acid, phthalic anhydride and the like. Unsaturated acids with carbon chains containing up to 35 carbon atoms, such as acrylic, crotonic, linoleic and linolenic acids are also of value. The acid or anhydride is reacted directly with ethylene oxide by incorporation with the aldehyde prior to addition of the oxide, or it may be reacted with dioxolane and aldehyde likewise by incorporation in the reaction mixture before refluxing by process illustrated in Example 3. The acids are used in minor quantities of up to about 50 mole percent of the total reactants.

I may also employ polyacetals containing end-stopping groups derived from aliphatic alcohols of from 1 to 35 carbon atoms. Such radicals may be introduced either by utilizing an aliphatic monohydric alcohol as a component of my reaction mixture along with the alkylene oxide or dioxane, or by employing as a coreactant a monoalkyl ether of ethylene glycol. Thus, I may employ methyl, ethyl, butyl, amyl, decyl, lauryl, cetyl, stearyl, or pentatriacontyl alcohol either as such or in the form of an ethylene glycol or trimethylene glycol or other glycol monoether. The rnonohydric alcohols may be reacted in various proportions by weight up to about 75 percent, depending upon the chemical composition desired, the molecular weight and properties sought. The preferred polyacetals contain monohydric alcohol residues in proportions up to equimolar amounts of the glycol residues therein.

A particular advantage of these materials for use in textile finishing is to be found in the fact that textiles so treated do not retain chlorine upon bleaching with chlorine. Thus, upon subsequent heating operations, as in ironing, hydrochloric acid is not released to tender the fabric.

In this invention I may use other aliphatic aldehydes and dialdehydes instead of formaldehyde. These include acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexaldehyde, heptaldehyde, 2-ethyl hexaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, pivaldehyde, and hydroxy adipaldehyde, or their polymers, precursors or simple derivatives.

Instead of 'an aldehyde, I may use its polymers or simple acetals. For example, in place of formaldehyde, I may use paraformaldehyde, trioxane, or methylal.

I may also modify the simplecondensation product with polyhydric alcohols containing from 3 to 6 hydroxyl groups and from 3 to 10 carbon atoms per molecule, such as glycerine, butanetriol, trimethylol ethane, trimethylol propane, pentaerythritol, mannitol, sorbitol, alpha-methyl glucoside, dipentaerythn'trol, and the like. These may be used in quantities up to 50 mole percent of the olefin oxide or dioxolane equivalent used.

The term cellulose material is intended to include filaments and fibers, staple or yarns, whether in finished stages or at some intermediate stage in the production thereof, of the group consisting of viscose rayon, and other forms of regenerated cellulose, cotton, jute, ramie, hemp and paper, whether woven, felted, or non-woven. Mixed fabrics and mixed papers composed of cellulose fibers and of non-cellulose fibers may also be treated in accordance with this invention. Films of regenerated cellulose are also included in this invention.

Sufficient catalyst and adequate curing condition are required to effect interaction between the reactants described herein and the cellulose material and thus no curing temperature upper limit may be set as this will depend on time of exposure of the cellulose material. The lower temperature limit for efiective cure is in the order of 250 F.

Other textile finishing agents, such as vinyl resins, starches and modified starches, softeners, and the like may also be employed as bath components during the treatment of textile cellulose materials in accordance with the process of this invention.

Iclaim:

1. The process of treating a cellulosic material which comprises applying to a cellulosic material an aqueous bath containing an acidic catalyst and a polymeric acetal condensation product derived from an alkylene oxide having not more than four carbon atoms in the alkylene nucleus and an aliphatic aldehyde containing 1 to 8 carbon atoms, said condensation product containing per molecule at least two oxyalkylene radicals derived from the said alkylene oxide and at least two alkylidene radicals derived from said aldehyde, said catalyst being present in amount from about 5% to about 200% by weight of said polymeric acetal condensation product, said polymeric acetal condensation product being present in said bath in amount from about 0.5% to about 25% by weight of the bath and heating the treated cellulosic material at an elevated temperature until the cellulose and said polymeric acetal condensation product react and dimensionally stabilize the cellulosic material.

2. The process of treating cellulosic materials as defined in claim 1, wherein the bath contains a polymeric acetal condensation product of ethylene oxide and formaldehyde.

3. The process of treating cellulosic materials as defined in claim 1, wherein the acetal condensation product is modified by an organic acid selected from the group consisting of aliphatic and carbocyclic acids having up to 35 carbon atoms.

4. The process of treating cellulosic materials as defined in claim 1, wherein the acetal condensation product is modified by a polyhydric alcohol containing from 3 to 6 hydroxyl groups and 3 to 10 carbon atoms.

5. The process of treating cellulosic materials as defined in claim 1, wherein the acetal condensation product is modified by an aliphatic alcohol having 1 to 35 carbon atoms.

6. Cellulose material dimensionally stabilized by the process as defined in claim 1.

References Cited in the file of this patent UNITED STATES PATENTS 2,395,265 Gresham Feb. 19, 1946 2,395,292 Peterson et al. Feb. 19, 1946 2,785,947 Kress Mar. 19, 1957 2,785,948 Abrams Mar. 19, 1957 2,785,949 Kress Mar. 19, 1957 2,785,995 Kress Mar. 19, 1957 

1. THE PROCESS OF TREATING A CELLULOSIC MATERIAL WHICH COMPRISES APPLYING TO A CELLULOSIC MATERIAL AN AQUEOUS BATH CONTAINING AN ACIDIC CATALYST AND A POLYMERIC ACETAL CONDENSATION PRODUCT DERIVED FROM AN ALKYLENE OXIDE HAVING NOT MORE THAN FOUR CARBON ATOMS IN THE ALKYLENE NUCLEUS AND AL ALIPHATIC ALDEHYDE CONTAINING 1 TO 8 CARBON ATOMS, SAID CONDENSATION PRODUCT CONTAINING PER MOLECULE AT LEAST TWO OXYALKYLKENE RADICALS DERIVED FROM THE SAID ALKYLENE OXIDE AND AT LEAST TWO ALKYLIDENE RADICALS DERIVED FROM SAID ALDEHYDR, SAID CATALYST BEING PRESENT IN AMOUNT FROM ABOUT 5% TO ABOUT 200% BY WEIGHT OF SAID POLYMERIC ACETAL CONDENSATION PRODUCT, SAID POLYMERIC ACETAL CONDENSATION PRODUCT BEING PRESENT IN SAID BATH IN AMOUNT FROM ABOUT 0.5% TO ABOUT 25% BY WEITHT OF THE BATH AND HEATING THE TREATED CELLULOSIC MATERIAL AT AN ELEVATED TEMPERATURE UNTIL THE CELLULOSE AND SAID POLYMERIC ACETAL CONDENSATION PRODUCT REACT AND DIMENSIONALLY STABLIZE THE CELLULOSIC MATERIAL. 